Granville t



(No Model.)

G. T. vWOODS. SYSTEM OF ELECTRICAL DISTRIBUTION.

N0..569,443. Patented Oct. 13, 1896.

WITNESSES: lNVENTOR THE nonms pztcns 1:0,. PHDTO LITHQu WASHINGTOFV. 0. c1,

UNITED STATES PATENT OFFIC GRANVILLE T. VOODS, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO S. E. RILEY, OF SAME PLACE.

SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 569,443, dated October 13, 1896.

Application filed February 5, 1896. Serial No. 578,157. (No model.)

To all whom it may C07t067lt.

Be it known that I, GRANVILLE T. Woons, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Electrical Apparatus for Lighting, &c., of which the following is a specification.

The object of my invention is to produce an economical, efficient, and safe system and method for controlling and operating electrical translating devices (such as lamps or motors) used in theaters and other places where it is often desirable to dim the lights at will or when it is desired to vary the current to control the motor operating an elevator. The system can be employed to the best advantage in forts and on war and other vessels where it is of great importance to economize in the use of fuel and space. lVhen used on war vessels, the lights may be dimmed to any desired degree, while electric motors may be arranged, in accordance with the spirit of the present invention, to handle guns, hoists, and steering apparatus with greater ease, certainty, quickness, economy, and sa fcty than by any other method known to me.

Prior to my invention it has been the practice to introduce a bulky mechanical resistance in series with the translating device to be controlled, so that the resistance will be compelled to absorb and waste by radiation all of the electrical energy between the maximum and the minimum amount required by the said translating devices when doing useful work. Such a method of control is very wasteful and dangerous, first, because the amount of electrical energy generated is greatly in excess of the amount employed in doing useful work, and, secondly, because of fire risk. In my system and method of control the amount of electrical energy generated is approximately in proportion to the useful work performed. This result is accomplished by arranging in the circuit between the constant-potental generator and the translating device a separately-excited variable-potential generator having means for varying at will the potential of the curout my invention.

rent delivered to the translating device to be controlled. It has been demonstrated by practice that a saving of forty per cent. is effected by the use of the present method instead of the former method herein described.

My invention will be more clearly understood by reference to the drawings, in which similar letters or figures of reference indicate corresponding parts in both the views of the drawings.

Figure 1 is a diagram view of the preferred arrangement of the system and apparatus illustrating the generators, translating devices, and other parts that aid in carrying Fig. 2 is a side view of a switch which controls one of the generators and also one of the translating devices.

In Fig. 1, A is a constant-potential compound-wound generator. \Vires E and F are the leads or mains.

B is a variable and reversible potential generator which is electrically connected to the bank of lamps I and controls the current operatin g the same.

0 is another variable and reversible potential generator which is in electrical connection with the reversible working motor D and controls the voltage of the current operating the motor.

His a bank of translating devices which are in direct electrical connection with the constant-potential generator and independent of the variable-potential generators. The space inclosed by the dotted lines J contains the switch apparatus for controlling the potential of generator-B. The space inclosed by the dotted lines K contains the switch mechanism by which the voltage of generator 0 is controlled and the reversal of motor D is accom plished.

1O, 11, 12, 13, 14, and 15 are flexible detachable conductors having common plug ends for making connections at will between the switches, the variable generators, and the translating devices controlled by them. lVires 1S and 11) electrically connect the armatures of generators l3 and 0 together through conductor G, which is connected to the line F.

They are also mechanically connected to-' being transmitted from the prime source'of power to the said counter-shaft through belts M and N.

It willbe observed that eonductor20 has one terminal connected to conductor E, while the other terminal, 23, is adapted to receive the plug end of the one of the said flexible conductors which connects the translating device to the armature of the variable-potential generator. This connection will be used at times. Forinstanee,in ease of the failure of belt M, or for any other reason it should be desirable to operate one of the variable generators,as a m otor, to drive the other variable generator it would be necessary to disconnect that machine from the translating device which it had previously controlled. 1f genera-tor B was to be used as a motor, flexible conductor 14 would be disconnected from terminal 22 and connected to terminal 23. The circuit through the variable-generator armature would then be across the leads or mains in multiple with its iieldanagnet. If generator 0 was to be used as a motor, flexible conductor 11 would be disconnected from terminal 21 and connected to terminal 23. The circuit would then be across the mains through the armature of the variable generator, the armature then being in multiple with its field-magnet. If it should become necessary to use generators B and O to supply all of the energy used by the motor, then switch-conductor 14 should be disconnected from 22 and connected to 23 and switch 45 should then be opened.

I will now explain the action of the variable-potential generators. It is well known that the potential of an inductive electric niaehine maybe varied by different means. The means which I prefer (because of its convenience) is the variation of the field of the generator. By employing a separately-excited variable field to Vary the potential one great advantage is that the conneeting-wires between the held-coil and the controlling-switch may be of any desired length and flexibility, so that the potential of the current may be controlled from the point where the translating device is located, or the said controllingswitch may be made portable, so that in case the translating device is used to operate an elevator or other traveling vehicle the controllingapparatus may be located on the moving conveyance.

It is well known that if the field of a gen erator is varied and reversed (when the armature is running in a constant direction) the electromotive force of the generator will be varied and reversed. To illustrate one of the great ad vantages of utilizing this phenomena to control translating devices, suppose the maximum potential of generators A, B, and C, respectively, to be one hundred and ten volts. Constant-potential generator A delivers current to the machines B and C. If the controlling-switch in the field-circuit of either of the variable generators is so adjusted that the voltage of the variable generator is at its maximum and opposes the voltage of the constant-potential generator, no current will flow to any translating device, but as the resistance is cut into the field-eircuit, thereby weakening the field, the translating device will begin to receive energy, having a potential equal to the difference between the voltage of the constant-potential current and the potential of the energy generated by the variable generator. As the field of the variable generator is being wealtened the variable potential will fall and the translating device will receive an increased potential proportioned to the fall of the electromotive force of the variable generator. \Vhen the field-circuit of the variable generator is opened, no current will be generated by the said variable generator, but the translating device will continue to receive energy from the constant-potential generator. The said energy now reaches the translating de vice at nearly the maximum voltage of the constant-potential generator. The continued movement of the aforesaid controlling-switch will reclose the field-circuit of the variable generator, but the direction of the current through the field-coil is thereby reversed. Therefore the magnetic poles of the field are reversed. At this point all of the resistance (on one side) of the field is in circuit. As the resistance is gradually cut out of the 'lleldcircuit of the variable generator the energy generated will flow in the same direction as the constant-potential current and its electromotive force will be added thereto until the maximum or required potential is reached. To reduce the potential, the reverse movement of the said controlling-switch takes place. It should be understood that the generators A, I and (l are not necessarily of the same capacity. I prefer to make generators l3 and 0 large enough to furnish the bulk of the current used in the translating devices controlled by them. In that case generator A would furnish the current for charging the field-magnets of the generators and also contribute a little energy for the purpose of boosting the voltage of generators B and C whenever such support became necessary. Translating devices requiringa constant potential, as shown at 11, may be fed by generator A. \V hen the variable generators B and C are of the ca pacity j ust mentioned, they are better adapted to stand the sudden strains that may be brought upon them.

In Fig. 2 the part 0 is an insulating-block, to which is affixed contact-blocks 6, '7, 8, and 9. These blocks and their holder 0 constitute the controlling-switch used to control generator 0 and to reverse the motor simultaneously. To these blocks are connected may be termed their initial position.

dicated at I.) It is obvious that the said switch can be arranged in the form of a lever for convenience in handling instead of in the form of slide illustrated.

I will now explain the action of generator B and the switch connections while the bank of lamps at I are being controlled. It will be observed that the lamps are arranged in multiple series between the conducting-wires, one of which, 20, is connected to main conductorE and also to the switclrcircuits within the dot ted lines J. The other conductor -wire is connected, through flexible conductor 14, to the armature of generator B, and the electrical communication extends through the said armature and conductors G and F to generator A.

The operation is as follows: Suppose the machines to be in operation. Then we close the switch shown at J. The upper finger 34 of the switch will make contact with the upper resistance 35, while the lower finger 36 will make contact with conductor 33. Current will then flow from conductor F through conductor 33 and the said lower finger 36 to flexible conductor 15, thence to the field of generator B and, returning through flexible conductor 13, to the said upper switch-finger 34 and the said resistance 35, thence to conductor 20 and then to conductorE. As we cut the resistance out of the circuit the electromotive force of generator B continues to rise and the lamps glow brighter until the maximum voltage is reached. If it should be desirable to reduce the amount of light without reducing the number of lamps in circuit, it is only necessary to reverse the movement of the switch at J until the desired reduction in light has been attained by cutting out resistance 37.

I will now proceed to explain the apparatus that is operated by, and the controllingswitch connected to, generator 0. Motor-D, as here shown, is of the variety known as long-shunt compound. During the opera tion of such a motor the field-magnet varies in strength each time the current varies in the armature. The series coil of the motor is provided with a switch 41, whereby the strength of the motor-field may be adjusted. The motor is provided with a brake 38, which is magnetically drawn toward the fie1d-magnot when the field is energized, but when the field has lost its power to hold the said brake then spring 40 draws the brake against plate 39, which is made fast to the armature-shaft. By means of the brake the load raised by the motor may be held at any point that may be desired.

It will be observed that the conductor leading from the lower brush of motor D is bifurcated at point 24. Switch-block 6 rests on one branch and 25 is the other branch. The conductor leading from the upper brush of motor D is bifurcated at point 2.6. Switch-block 7 rests on one branch and 27 is the other branch. Itwill be observed that while switchblock 6 rests on a branch which leads from the lower brush of motorD a branch 27, leading from the upper brush, lies in a direct line with the branch on which block 6 rests. Switchblock 7 rests on a branch which leads from the upper brush of motor D, while branch 25, leading from the lower brush, lies in a direct line with the branch on which block 7 rests. The object of this arrangement is that when the switch is being moved and blocks 6 and 7 cross from the branches on which they now rest to branches 27 and 25, which lie in the paths of the said blocks, motor D will be reversed.

Cond uctor 28 has two terminals which are in a direct line with and point toward each other. Both terminals end in resistances, as indicated by the conventional representation of a coil. Switch-block 8 rests on one of the terminals and 29 is the other terminal. Contactstrip 30 also has a resistance connected to each end and an electrical connection is main taiued between the said strip and conductor 28. In a direct line with and leading from positions opposite the ends of strip 30 there are two contact-strips. Switch-block 9 rests on one strip while 31 is the other strip. The last-mentioned strips are parallel to but separated from the strips which are the terminals of conductor 28. Con tact-strip 32 is arranged in a direct line with and between the terminals of conductor 28. Contact-strip 32 is electrically connected to strip 31 and also to the strip upon which switch-block 9 rests. One terminal of the field of generator 0 is connected through flexible conductor 12 to the contact-strip upon which switch-block 9 rests. The other terminal of the said field is connected through flexible conductor 10 to conductor 28.

The vertical dotted lines 1, 2, 3, 4, and 5 represent different switch positions, which will be explained more clearly hereinafter.

The operation of generator 0 and its controlling-switch and the motorD will be as follows: Suppose the generators to be in operation and motor D to be raising weight P, the switch-blocks 6, 7, 8, and 9 being in position 1, as shown in the drawings, then the motor would be receiving the maximum electromotive force of generatorAthrough conductors F, G, and 19, armature of generator 0, flexible conductor 11, switch-block 7, and conductor 42. The return-current leaves the lower brush of the motor and passes to point 24, thence to switch-block 6, thence over conductor 43 and through the coarse or series coil on the field-magnet, thence along conductors 44 and E to the generator A. As the current passes through the armature of generator 0 erator C, thereby weakening the lleld and consequently lowering the electromotive force generated in its armature. hen the switch has reached the vertical dotted line 2, switchblocks 8 and 9 will have opened the field-circ uit of generator 0. Therefore no current will be generated by the armature while the switch occupies this position. Consequently all of the energy that reaches the motor-armature will be received from generator A. Continued movement of the switch in the direction of the vertical dotted line 3 will cause block 8 to make contact with conducting-strip and block 9 will make contact with the nearest rcsistanee-terminal of conducting-strip 30. This new connection will cause the field-current to pass through the field-coil in a direction reverse to that in which it formerly flowed. Consequently thefield magnetism has been reversed and the electromotive force which is being generated in the armature has changed its course of movement and operates to oppose the electromotive force from generator A. As the switch movement is continued toward position 3 block 9 cuts the aforesaid resistance of conductor 30 out of the circuit. Therefore the electromotive force generated by the armature of machine 0 has increased and annulled the energy from generator A. In the meantime, since the switch has passed position 2, block 7 (which will be noticed is longer than blocks 0, S, and 9) has spanned the space intervening between the conducting-strip upon which it rests and strip 25, thus short-cireuiting the motor-armature before the armature-eireuits are reversed, thereby utilizing any current that may be generated in the motor-armature at that moment to aid in bringing the armature to rest. The switch having passed position 3 and block 6 being in contact with conducting-strip 27 and block 7 being in contact with strip 25, both blocks having deserted their former cond ucting-strips,the motor-armature circuit will thereby be reversed. If now we desire to start the motor reversed, the switch must be moved farther toward the vertical dotted line a. Block 9 will then gradually cut the remaining resistance of conductor 30 into the field-circuit of generator 0, thereby reducing the electromotive force generated in the armature of the machine, and thus allowing energy from generator A to reach the armature of motorD. As the switch is moved to position 4 the field-circuit of generator 0 will again be opened, but when the switch has passed position 4E block 8 will make contact with the resistance of strip 29, while block 0 will make contact with strip 31. The new connections have reversed the field of generator 0, and as the switch moves toward the vertical dotted line 5 the resistance of strip 29 will be cut out of the field-circuit. hjleanwhile the electromotive force of generator O has been increasing and added to that of generator A.

It is obvious that when motor D is used for hoisting the electromotive force of the current supplied to the motor-armature must be increased until the torque of the motor evercomes the effect of gravity on the load hoisted, (here typified by a weight P.) The mo tor may be reversed and the load may be lowered in three waysby reducing the electromotive force supplied to the motor-armature until the load causes the armature to turn in the opposite direction, or by cutting off the supply of current to the motor and allowing the armature to be rotated in the opposite direction under the influence of the load and controlled by the brake S 39 to regulate the descent of the load, or by reversing the direction of the current through the motor.

It should be understood that the relative capacities and voltages of the machines would be governed by the conditions under which the system had to work and also by the judgment of the engineer installing the system. It will be observed that the flexible conductors herein mentioned may be used as switch connections for changing the generators from one circuit to another.

I do not limit myself to the precisearrangement of circuits or the form of generator or motor used, as I may vary widely from the construction shown and described without departing from the spirit of my invention. For instance, I may use either compound, series, or shunt motors with or without l'OVOl'Sh ble fields in carrying my invention into effect.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The method of operatingand regulating the work of an electric motor, consisting in maintaining one coil of the field-magnets of the electric motor at a constant strength, supplying its armature from a source of constant potential, supplementing the electromotivo force of said source by electromotive force from a supplementary source, varying the electromotive force of said supplementary source and at the same time varying the strength of the field-magnet of the motor, substantially as described.

2. The method of regulating and controlling electric-power apparatus, consisting in supplying current to two electrodynamic machines whose armatures are in series with each other, and regulating the electromotive force of one of the machines to control the other machine by driving the armature of the regulating-machine at a practically constant speed and varying its field and simultaneously varying the field of the machine to be controlled, substantially as described.

3. The method of regulating and controlling electric-power apparatus, consisting in, supplying current to two elcctrodynamic machines whose armatures are in series with each other, and regulating the eleetromotive force of one of the machines, both in amount and direction, to control the other machine, by maintaining the speed and connections of the armature of the regulating-machine practically constant and varying and reversing its field While at the same time varying the field of the other, substantially as described.

4. The method of reversing an electric motor, supplied with current from a constantpotential source and from a supplemental source, consisting in magnetically producing at the supplemental source a counter electromotive force independently of the motor and thereby reducing to the minimum the electromotive force supplied to the motor and then reversing the motor, substantiallyas set forth.

5. The method of performing work by an electric motor supplied with current from a variable generator and a constant-potential generator, which consists in simultaneously and differentially varying the field-magnet strength of the variable generator and the motor, Without changing the fieldmagnet strength of the constant-potential generator, substantially asset forth.

(5. The combination of a constant-potential generator having conductors leading therefrom and a translating device, a second generator having its armature operating in a variable magnetic field, said armature being in electrical connection with the said conductors and also in connection with the translating device, and a switch mechanism the two parts of which are mechanically connected for operation and so arranged that one part controls the variation of the field of the said second generator while the second part controls the reversing of the translating device, substantially as set forth.

7. In combination with a constant-potential generator having conductors leading therefrom and a motor, a second generator having its armature operating in a variable magnetic field, said armature being in electrical connection with said conductors and also in connection with the motor, and switch mechanism having four movable contacts insulated from each other and mechanically connected for simultaneous operation, two of said 0011- tacts being in movable electrical connection with the terminals of the field-circuit of the said second generatoigthe two remaining movable contacts being in movable electrical connection with the reversing-terminals of the motor, substantially as set forth.

8. In combination with a constant-potential electrical generatorhaving conductors leadin g therefrom and a translating device, a second electrical generator having its armature operating in a varying magnetic field, said armature being in constant permanent electrical connection with the said conductors and also in connection with the translating device and switch mechanism whereby the said varying magnetic field is controlled and the translating device reversed simultaneously.

9. The combination with a constant-p0tential generator and a supplemental generator of a motor receiving current from said generators, and aregulating and controlling switch between the supplemental generator and the motor provided with contacts and connections for varying the electromotive force of the supplemental generator, and contacts for reversing the motor and for placing it on short-circuit in the transition between direct and reverse operation, substantially as set forth.

Signed at New York, in the county of New York and State of New York, this 31st day of August, A. D. 1892.

GRANVILLE T. XVOODS.

\Vitnesses:

W. S. HANFORD, O. H. WILLIS, LIZZIE Woons. 

